At first blush, a poll showing Mitt Romney trailing Newt Gingrich among likely Iowa caucus goers shouldn’t be too worrying for the former Massachusetts governor’s campaign. There’s been a steady ebb and flow of chief competitors this fall and, although Romney recently started investing heavily in the state he long ignored, Iowa was never going to be the battleground on which Romney’s candidacy won or died. But the internals of a new Washington Post/ABC News poll showing Gingrich with a robust lead hint at a potentially broader problem: Voters there simply haven’t been buying what he’s been selling.

From its outset, Romney’s candidacy has been predicated on the notion that the strength of his experience in the private sector makes him uniquely qualified to handle the economy, the issue of chief concern to a majority of Americans at this moment. But the Post poll found that among those who named the economy or budget deficits as their top priority, Gingrich beat out Romney by 14 points. Similarly, Romney has long argued that his economic bona fides make him the most likely candidate to defeat President Obama, historically a powerful consideration in Republican primaries. Iowa voters haven’t fully taken that argument to heart either; likely caucus goers named Gingrich the more viable general election candidate by 5 points.

In seeking to draw a contrast with his competitors, especially Gingrich, Romney has repeatedly noted that the former Speaker was a “career politician,” while he spent most of his life in business. That message might be getting through, but the Post poll suggests it’s not having the desired effect. Seventy percent cited Gingrich’s political experience as a reason to support his candidacy, while just 11% said it gave them cause to oppose it. Comparatively, 61% said Romney’s business experience was a plus, and 7% counted it against him–not at all bad, but clearly not the leg up on Gingrich he’s been working for.

Romney has also tried to sow doubt about Gingrich among conservative voters by assaulting his position on illegal immigration–Gingrich favors a path to legal status for some undocumented workers currently living in the country. But Iowa voters’ views on Gingrich and immigration don’t reflect much unease: 38% say it makes them more likely to support him, 36% say it makes no difference and 15% cite it as a reason to cast their ballot for someone else. Romney, meanwhile, is being seriously hurt by his record on health care reform–presumably his support for an individual mandate that Gingrich also once supported and that went on to serve as a pillar of Obama’s national reforms. The survey found that 45% say Romney’s record on health care makes them more likely to oppose his bid with 14% and 34% saying it’s a plus or non-factor respectively.

There are other important factors in the poll and Romney has only recently begun to contest Iowa. A month of aggressive advertising and two in-state debates could certainly shift these sentiments. But Romney has virtually been running for President since the close of the 2008 election. His coast-to-coast drumbeat for three years has been that he has the economic credentials to oust Obama. And as the specter of a Gingrich surge loomed, he did not hesitate to draw a sharp contrast and attack on immigration. After all that, it doesn’t appear to have sunk in, at least in the first caucus state. And that spells trouble.